A flash smelting furnace is a smelting furnace used in a smelting of oxide of nonferrous metal such as copper or nickel and a matte smelting. In the flash smelting furnace, an apparatus for supplying raw material and reaction gas into a furnace acts as an important function for determining property of the flash smelting furnace. The property of the raw material supply apparatus determines reaction efficiency and reaction progress of the raw material in a reaction shaft, and thereby determines the property and metal loss of the flash smelting furnace. It is preferable that the reaction in the reaction shaft of the flash smelting furnace progresses speedy and all raw materials react equally at the same progress rate. It is preferable that the reaction between the raw material and the reaction gas supplied into the furnace is completed in the reaction shaft. It is important to mix the raw material and the reaction gas equally in order to complete the reaction early and equalize the reaction.
Japanese Patent Application Publication No. 04-121506 and Japanese Patent Application Publication No. 2007-46120 disclose an art making spiral flow of main blast supplied into a reaction shaft from a raw material supply apparatus or controlling flow rate of the main blast in order to improve a mixing of raw material and reaction gas. Japanese Patent Application Publication No. 2002-241855 discloses a method of burning raw material in a shaft and increasing raw material temperature in order to complete a reaction in a reaction shaft early.
However, fuel cost may be increased in a case of burning a fuel in the shaft. Use of fossil fuel should be avoided in view of environmental problem. There is no report that a method of mixing the raw material and the reaction gas improves reaction condition dramatically.